Obinna K. Ihesiulor
University of New South Wales
Title: Investigation of wear in orthopaedic hip prosthetic devices
Biography
Biography: Obinna K. Ihesiulor
Abstract
Total hip replacement (THR) is one of the most popularly performed operations in orthopaedics as evident in clinical outcomes. Potentially, an approximate of 400,000 hip joint replacement procedures is performed each year in the U.S. However, studies have identified that majority of hip implants are prone to wear at the taper-trunnion junction. The taper-trunnion (head-stem) is essentially the interface between the ball of the hip joint which articulates with the pelvis and the hip stem which is constrained rigidly to the femur bone. The head and stem components connect at a taper on the hip head and a trunnion on the hip stem. This junction is of peculiar and remarkable interest because it is associated with excessive fretting wear due to the taper sliding relatively against the trunnion. Excessive fretting wear at the taper-trunnion junction (trunnionosis) apparently contributes to the high failure rates of hip implants. Implant wear and corrosion lead to the release of metal particulate debris and subsequent release of metal ions at the taper-trunnion surface. This results in a type of metal poisoning referred to as metallosis. The consequences of metal poisoning include; osteolysis (bone loss), osteoarthritis (pain), aseptic loosening of the prosthesis and revision surgery. Follow up after revision surgery, metal debris particles are commonly found in numerous locations. To investigate the feasibility of reducing wear in taper/head-trunnion/stem (head-stem) joints in hip implants by the use of cylindrical/parallel head-stem joints instead of the currently used tapered stems.